Project Summary/Abstract It is well established that language is fundamentally interwoven with human cognition. Even before infants understand the meaning of a single word, listening to language supports cognitive processes such as rule learning (Ferguson & Lew-Williams, 2016) and category formation (e.g., Balaban & Waxman, 1997; Ferry, Hepos & Waxman, 2010; Fulkerson & Waxman, 2007). Yet the mechanisms through which language exerts these effects in infancy are not well understood. The aim of the current proposal is to identify the potential visual attentional mechanisms that might underlie the effects of language on cognition, across two visual tasks (object comparison and object categorization), across 2 developmental time points (5 and 10-months), and across two language modalities (spoken and signed language). In order to understand how language affects infant cognitive processes, the proposed studies will use eye-tracking to explore visual indices such as pupil dilation and fixation patterns that have previously been of interest to vision researchers but unexplored by language researchers. This set of studies will ask how language organizes attention, and which individual differences in attention are most predictive of learning outcomes. Two experimental paradigms will be used: one that requires infants to encode individual objects and detect when they have changed, and one that requires learning object categories. Studies within each series will first examine visual measures in the absence of language, and will then compare the influence of language vs. non-linguistic cues. A final study will ask how the observed effects translate across language modality by testing how infants respond to seeing sign language, rather than hearing spoken language. This research will advance the field's understanding of how language affects attention and cognition in infancy. Moreover, the studies are designed to leverage individual differences in infant attention. A clearer understanding of normative attention patterns in the infant years will serve as a springboard for identifying targeted interventions with long- term benefits for infants and young children at risk for attention disorders and ASD. Finally, studying how infants allocate their attention in the context of seeing sign language will provide much needed basic research on the processes that underlie language development in children who are born deaf or hard of hearing due to chronic ear infections. This research will also provide the applicant with critical training to advance her academic career. This includes methodological training in infant eye tracking methodology and analysis techniques, as well as theoretical training in visual attention processes ? a topic her graduate training did not include. Finally, the proposed experiments provide a clear extension of her graduate research program which focused on how non-verbal communicative cues (gestures) influence learning in children. By extending her research focus and gaining new methodological skills, she will grow as a researcher and advance her professional opportunities.